A non-immunoglobulin salivary agglutinin system (NIA) has been partially isolated via DEAE - Sephadex A-25 ion exchange chromatography. When NIA was applied to standard 9.0% SDS polyacrylamide gels, a major low molecular weight band appeared near the dye front. In addition, several minor bands with molecular weights greater than 200,000 were also present. The low molecular weight component of the NIA system is abbreviated LMSA. Our preliminary studies suggest that NIA agglutinates erythrocytes coated with complement and fibronectin. We speculate that NIA, in particular the LMSA might play a role in the adherence of bacteria to mucosal cell surfaces. The objectives of this pilot research project are to develop better procedures for isolation of substantial quantities of LMAS which will be needed for biological tests, and to begin to chemically characterize this substance.